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Windows TCP/IP stack implementation details

Question

We have two applications running on the same Windows system (they can run on Windows XP, Windows Vista, Windows 7, probably on Windows 8 as well, but we haven't tested them yet). The applications communicate with each other via TCP/IP.

If the systems do not have a loopback adapter configured, is the network card used during the communication?

Are there situations where, even with a loopback adapter configured, the network card is used during communication?

Even more, the answers to the questions above depend on the Windows version?

We're asking this because we're seeing strange behavior at a client, where one application reports in the logs that it is properly sending the data to its communication partner, but the communication partner reports it is receiving corrupted data. We have
to ask for special permission to install network monitoring software and, to do this, we need documented answers to the questions above.

Any hint towards a TechNet or MSDN page that properly documents this behavior is really appreciated.

Answers

Do you mean the two applications will communicate with each other? I just know that the loopback adapter is used when the machine needs network connectivity within itself. You can refer to the link below.

Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Do you mean the two applications will communicate with each other? I just know that the loopback adapter is used when the machine needs network connectivity within itself. You can refer to the link below.

Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

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